WASHINGTON — The Obama administration moved aggressively Thursday to reassert federal power and block state laws that allegedly violate the civil rights of minority voters, an authority that the Supreme Court had substantially weakened last month by striking down a portion of the Voting Rights Act.

The announcement by Atty. Gen. Eric H. Holder Jr. made Texas the administration's test case and first target, all but guaranteeing a full-scale political and legal battle with that state's conservative Republican leadership.

The battle comes with big stakes. Immediately in the aftermath of the Supreme Court's decision, several states, particularly in the South, announced plans to reinstate stringent voter ID laws and other practices that administration officials and civil rights groups see as aimed at reducing minority voting.

The consequences in Texas are characteristically large. It is by a wide margin the biggest reliable Republican stronghold left among the states, but it has a rapidly growing number of minority voters who lean toward the Democrats.

Holder said the Justice Department would go to court to seek an order that would once again require Texas to submit all proposed voting-law changes to Washington for advance approval. That practice, known as pre-clearance, had been the law from 1965 until the Supreme Court's ruling for nine Southern states, as well as parts of others, including California and New York.

Texas' plan for redrawing political boundaries after the 2010 census intentionally discriminated against minorities, administration lawyers argue, citing judicial rulings on that point as evidence that the state needs continued federal supervision.

The Texas filing is the department's first legal action in response to the Supreme Court ruling that altered the Voting Rights Act, "but it won't be our last," Holder said in a speech before a meeting of the National Urban League in Philadelphia, hinting at similar actions in other states.

"We plan … to fully utilize the law's remaining sections to ensure that voting rights of all American citizens are protected," he said.

In Texas, Gov. Rick Perry reacted heatedly.

"Once again, the Obama administration is demonstrating utter contempt for our country's system of checks and balances, not to mention the U.S. Constitution," said Perry, a Republican. "This end run around the Supreme Court undermines the will of the people of Texas, and casts unfair aspersions on our state's common-sense efforts to preserve the integrity of our elections process."

Texas Atty. Gen. Greg Abbott, considered the front-runner to succeed Perry as governor, accused the Obama administration of colluding with the state's Democratic Party. "This is an abuse of the Voting Rights Act for partisan, political purposes," he said, "to put Texas elections under their thumb."

Until last month's 5-4 Supreme Court decision, pre-clearance applied automatically to the nine Southern states. The goal was to end the widespread practice of crafting voting laws to prevent blacks — and later Latinos — from registering and casting ballots.

The court ruled that Congress had erred when it last renewed the law because it continued to use outdated voting information from the 1970s to decide which states would be covered by the pre-clearance rules. Although the decision gave Congress the ability to come up with a new coverage formula, there seems little chance of congressional action.

Indeed, the administration's announcement, which immediately triggered a strong rebuke among Republicans in Congress, seemed based in part on the belief that the chance of congressional action was so small that there was little to lose by moving unilaterally.

The new effort will employ a little-used part of the Voting Rights Act that was not affected by the recent high court ruling. Under this provision of the law, the federal government can gain authority over election laws in a state if a court has found practices there to be intentionally discriminatory.

"There is a reason they started with Texas," said Spencer Overton, a professor of law at George Washington University. "It is pretty clear it has been one of the most flagrant violators of the Voting Rights Act."

A panel of federal judges in 2012 found that the state's congressional redistricting map "was enacted with a discriminatory purpose" — undercutting the power of black Democrats and diluting the voting power of a surging Latino population.

"The only explanation Texas offers for this pattern is 'coincidence,'" the court wrote. "But if this is coincidence, it is a striking one indeed. It is difficult to believe that pure chance would lead to such results."